Uncontrolled Roll on Full Flaps

[TJay]

If the center mixer that controls the flaps is not level in the plane one side might drop further than the other. I would check that first also if you have one flap bearing on the wing that needs oil it may cause the stick to move when pulling on the flaps. But most of all you keep the plane level with your feet not the stick. If it starts to roll step on the pedal dont be shoving the stick around that will just make it worse ( adverse Yaw)

[LSaupe]

In addition to my previous, there is also a criteria for max flap extension whereby you set your stick to full deflection to left or right and pull flaps on until the stick starts to move towards center. That becomes your new max flap extension, which might be less than 20 degrees. 20 degrees or stick motion being the limiting factor.

[TY2068]

I read were some guys with early models would tweak the trailing edges of the Flaperons (one up, one down) to help with wing drop. I guess doing that was a last resort when nothing else helped. I'd also guess some of these planes were slapped together and not assembled correctly.